Erykah Badu may have one of the most acclaimed back catalogues of any active R&B artist, but she has always seen herself as a live performer first and foremost: "I shine on the stage," she has said. London is a regular tour stop – even when she has no new material to promote, like now – but what continues to be remarkable are the myriad ways Badu finds to recast her music each time.

Her songs seem to have endless permutations of arrangements: instead of set melodies and structures to be rigidly adhered to, in Badu's hands they sound like living, breathing and growing entities. Appletree begins languorously, a perfect soundtrack for the humid evening, before veering into ferocious electro beats and culminating in Badu scat singing over triumphant horns; I Want You opens with sonorous drums and ends with Badu interpolating her own hook from Common's All Night Long while shaking a tambourine. When covering Outkast's Liberation, she takes on Big Boi and André 3000's verses as well as her own; by the end of the song, they belong to her as well.

Tonight also finds Badu in particularly robust form, far from the dreamy reverie she sometimes chooses to employ. 20 Feet Tall opens the show with a declaration of power, slowed so Badu can savour the words on her lips. The Healer's stop-start arrangement emphasises the radicalism of its lyrics. The high drama and urgency of Danger is magnified by a tough, snappy arrangement and ominously gothic backing vocals. Badu lets out full-throated, primal hollers in most of tonight's songs – but between songs seems relaxed and almost playful at times. With no new album to focus on, she picks songs from her discography at her leisure, perhaps surprisingly paying most attention to 2003's underrated Worldwide Underground release.

Reasons to believe Badu to be one of the best R&B performers of her generation have never been in short supply; tonight, she only confirms them.